Unless otherwise indicated herein, the approaches described in this section are not prior art to the claims in this disclosure and are not admitted to be prior art by inclusion in this section.
Linear beam electron devices are used in sophisticated medical, security inspection, communication, and radar systems that require amplification of a radio frequency (RF) or microwave electromagnetic signal. An electron gun is a component in some vacuum devices (e.g., electron devices, vacuum electron devices, or vacuum electric devices) that ideally produces a collimated electron beam that has a precise kinetic energy. The electron gun can be used in microwave linear beam vacuum tubes, such as klystrons, inductive output tubes, travelling wave tubes (TWT), backward wave oscillators, and gyrotrons, as well as in scientific instruments, such as electron microscopes, betatrons, and particle accelerators (e.g., linear particle accelerator [linac]). Electron guns may be classified by the type of electric field generation (e.g., direct current [DC] or radio frequency [RF]), by emission mechanism (e.g., thermionic, photocathode, field emission, or plasmas source), by focusing (pure electrostatic or with magnetic fields), and by the number of electrodes.
A conventional klystron is an example of a linear beam electron device used as a microwave amplifier that includes an electron gun. In a klystron, an electron beam is formed by applying a voltage potential between a cathode emitting electrons and an anode, accelerating these emitted electrons such that the cathode is at a more negative voltage with respect to the anode. The electrons originating at the cathode of an electron gun thereafter propagate through a drift tube, also called a beam tunnel, and are received by a collector assembly.
Depending on the size of the vacuum device, a cathode assembly (e.g., including the cathode, focus electrode, and associated heater assembly) of the electron gun assembly of the vacuum device can be quite large or heavy and difficult to align with the rest of the device (e.g., the drift tube or the beam tunnel). The support and alignment of electron guns used in high power microwave devices and accelerators can affect the operation of the device or accelerator. In large klystrons, and in particular sheet beam klystrons (SBKs), the cathode assembly can weigh over 20 pounds (lbs; 9 kilograms [kg]), and in some klystrons the cathode assembly can even weigh over 50 lbs (23 kg). The technology (systems, devices, and methods) described herein provides mechanisms to support and align an electron gun in a vacuum device.
Often during operation, the cathode assembly can generate an excessive amount of heat and thermal stress, i.e., high thermal load. The heat and thermal stresses on the components of the vacuum device, especially the cathode assembly, can lead to stress values greater than the yield strength of critical components of the vacuum device, such as the support and alignment features. The technology (systems, devices, and methods) described herein provides mechanism to increase thermal dissipation (i.e., decrease thermal loading) in particular locations of the electron gun, such as the support structure or alignment features.